1. Field of the Invention
The present invention relates to an ink-jet recording head, in which part of a pressure generating chamber communicating with a nozzle orifice for ejecting ink droplets is composed of a vibrating plate and a piezoelectric element is formed on a surface of this vibrating plate so as to cause ejection of ink droplets by displacement of the piezoelectric element, a method of manufacturing the same, and an ink-jet recording apparatus.
2. Description of the Related Art
An ink-jet recording head, in which part of a pressure generating chamber communicating with a nozzle orifice for discharging ink droplets is composed of a vibrating plate, and which causes discharge of ink droplets out of the nozzle orifice by displacing this vibrating plate with a piezoelectric element and thereby pressurizing the ink in the pressure generating chamber, has two types that are already in practical use, namely, one using a piezoelectric actuator of a longitudinal vibration mode which expands and contracts in an axial direction of a piezoelectric element, and one using a piezoelectric actuator of a flexural vibration mode.
The former type effectuates fabrication of a head suitable for high-density printing because the volume of the pressure generating chamber is made variable by allowing an end surface of the piezoelectric element to abut on a vibrating plate. On the other hand, the former type incurs a problem in that the fabrication process is complicated due to the difficult process of cutting the piezoelectric elements into comb-teeth shapes so as to be aligned with an array pitch of the nozzle orifices, and an operation of positioning and fixing the cut piezoelectric elements onto the pressure generating chambers are required.
On the contrary, the latter type effectuates formation of piezoelectric elements on a vibrating plate by a relatively simple process of attaching a green sheet made of a piezoelectric material shaped to the pressure generating chambers and then by baking the green sheet. However, the latter type incurs a problem that high-density arrangement becomes difficult because a certain degree of area is required for utilizing flexural vibration.
Meanwhile, in order to solve the inconvenience of the latter recording head, as shown in Japanese Unexamined Patent Publication No. 5(1993)-286131, a recording head is proposed in which a uniform piezoelectric material layer is formed on an entire surface of a vibrating plate by use of a film-deposition technology, and this piezoelectric material layer is cut into shapes corresponding to the pressure generating chambers by a lithography method to form piezoelectric elements individually for the respective pressure generating chambers.
According to this technology, an operation of attaching piezoelectric elements to a vibrating plate becomes unnecessary. Therefore, the technology provides not only a capability of forming the piezoelectric elements in high density by use of the accurate yet simple technique called the lithography method, but also provides an advantage that high-speed drive can becomes feasible by virtue of reducing the thickness of the piezoelectric elements.